"The designs are striking a chord. They make terrific gifts. Some of them are funny, some are a little more serious.

"It's zeitgeist. The spirit of the British is very much to smile and get on with things in the face of adversity," added Martin, who is just old enough to remember the final days of rationing in the years that followed the Second World War.

Among the designs which have proved most popular are Keep Calm And Carry On and Dig For Victory, which has found favour with gardeners in particular.

Some of these historic slogans and exhortations have taken on slightly different meanings with the passing of time, such as "Rally Round The Flag - Every Fit Man Wanted".